An optical network communication system includes an optical hub, an optical distribution center, at least one fiber segment, and at least two end users. The optical hub includes an intelligent configuration unit configured to monitor and multiplex at least two different optical signals into a single multiplexed heterogeneous signal. The optical distribution center is configured to individually separate the at least two different optical signals from the multiplexed heterogeneous signal. The at least one fiber segment connects the optical hub and the optical distribution center, and is configured to receive the multiplexed heterogeneous signal from the optical hub and distribute the multiplexed heterogeneous signal to the optical distribution center. The at least two end users each include a downstream receiver configured to receive one of the respective separated optical signals from the optical distribution center.

A transmission/reception system includes: a second transmission/reception device configured to convert a multiplexed signal into a first digital signal in a first format, convert the signal into a first analog signal, and convert the signal into a second optical signal, and convert a first electrical signal into a second digital signal, demodulate the signal to generate a third digital signal, and output a plurality of sixth optical signals; and third transmission/reception device configured to convert a second electrical signal into a fourth digital signal, and demodulate the signal to generate a plurality of fifth digital signals; and convert a plurality of sixth digital signals into a seventh digital signal in a second format, convert the signal into a second analog signal, and convert the signal into a fourth optical signal.

A network or system in which a hub or primary node may communicate with a plurality of leaf or secondary nodes. The hub node may operate or have a capacity greater than that of the leaf nodes. Accordingly, relatively inexpensive leaf nodes may be deployed to receive data carrying optical signals from, and supply data carrying optical signals to, the hub node. One or more connections may couple each leaf node to the hub node, whereby each connection may include one or more spans or segments of optical fibers, optical amplifiers, optical splitters/combiners, and optical add/drop multiplexer, for example. Optical subcarriers may be transmitted over such connections, each carrying a data stream. The subcarriers may be generated by a combination of a laser and a modulator, such that multiple lasers and modulators are not required, and costs may be reduced. As the bandwidth or capacity requirements of the leaf nodes change, the number of subcarriers, and thus the amount of data provided to each node, may be changed accordingly. Each subcarrier within a dedicated group of subcarriers may carry OAM or control channel information to a corresponding leaf node, and such information may be used by the leaf node to configure the leaf node to have a desired bandwidth or capacity.

Methods, systems, and devices for a decision directed multi-modulus searching algorithm are described. A receiver may receive a signal including a set of data symbols. The receiver may iteratively determine a set of centroids for demodulating the set of data symbols (e.g., as part of a training procedure). The centroids may be used to demodulate the set of data symbols according to a modulation constellation associated with the set of data symbols. The training procedure may include, for each data symbol of a subset of data symbols, assigning a centroid of the set of centroids to each data symbol and updating the set of centroids based on assigning the centroid to each data symbol. The receiver may demodulate the set of data symbols based on the updated set of centroids.

A multiplexing device for multiplexing uplink signals transmitted from each of a plurality of radio devices and outputting the multiplexed signal to a radio control device performs a calculation processing that calculates a power value of the uplink signal for each radio device, performs a determination processing that determines whether or not noise of a radio device that transmits an uplink signal is dominant among signal components included in the uplink signal, using the power value of the uplink signal, performs a blocking processing that blocks the uplink signal in which the noise is dominant in a case where the noise is determined to be dominant among the signal components included in the uplink signal, and performs a multiplexing processing that multiplexes uplink signals that are not blocked among the uplink signals for each radio device, and outputs the multiplexed signal to the radio control device.

An optical network system includes an optical line terminal, an optical splitter that is connected to the optical line terminal via one first optical fiber, and a plurality of optical network units that are connected to the optical splitter via respective second optical fibers. The plurality of optical network units communicate with the optical line terminal using an optical signal of a working wavelength uniquely assigned to each of them. The optical line terminal communicates with an optical network unit that is connected to the optical splitter using an optical signal of a working wavelength and an optical signal of a spare wavelength that is common to a plurality of optical networks.

A transmitter can include a laser operable to output an optical signal; a digital signal processor operable to receive data and provide a plurality of electrical signals based on the data; and a modulator operable to modulate the optical signal to provide a plurality of optical subcarriers based on the plurality of electrical signals. One of the plurality of subcarriers carries first information indicative of a first portion of the data in a first time slot and second information indicative of a second portion of the data in a second time slot. The first information is associated with a first node remote from the transmitter and the second information is associated with a second node remote from the transmitter. A receiver as well as a system also are described.

Provided herein are various improvements to laser communication ranging. In one example, a method includes converting a ranging signal in a radio frequency (RF) format into an optical format and combining the ranging signal in the optical format with data communications into an optical transmission for receipt by a communication node. The method also includes receiving from the communication node an additional optical transmission comprising additional data communications combined with a retransmitted version of the ranging signal, and determining an indication of a range to the communication node based at least on properties of the retransmitted version of the ranging signal.

A Passive Optical Networks (PONs) structure and a remote node in such a structure constituting at least a part of a backhaul network for supporting a Radio Access Network, in which a number of radio base stations are connected to optical networks units (ONUs) of said PONs structure. The ONUs of said PONs structure are grouped between separate PONs of said PONs structure. The ONUs of a separate PON are interconnected passively through a remote node of the PON in order to separate inter base station traffic of X2 interfaces from uplink and downlink data traffic of S1 interface heading from/to a core network via an optical line terminal (OLT). The remote node comprises of power splitter for enabling interconnection between ONUs of different PONs of said PONs structure.

An optical communication system includes an optical transmitter, a plurality of optical receivers, and a splitter that splits light transmitted by the optical transmitter to the plurality of optical receivers. The optical transmitter includes a variable-wavelength light source capable of transmitting light of a first wavelength and light of a third wavelength between the first wavelength and a second wavelength. A first optical receiver of the plurality of optical receivers includes a first optical filter having a first transmission band including the first and third wavelengths, and a first receiving unit that receives light having passed through the first optical filter. A second optical receiver of the plurality of optical receivers includes a second optical filter having a second transmission band including the second and third wavelengths, and a second receiving unit that receives light having passed through the second optical filter.